It is a well known fact that during earthquakes, in addition to the primary damage caused by the tremors and vibrations, which can be of a very high amplitude, a great deal of secondary damage due to fires and flooding also occurs. Despite this, and despite the well known fact that California is due for an earthquake of major proportions, dwellings and other structures are not typically provided with automatic shut-off valves in gas lines and other fluid fuel lines, such as propane or oil. Once gas lines have been ruptured by the trauma of an earthquake and the ruptured lines fill buildings with highly flammable gases, any spark or remaining pilot light can trigger a conflagration that may leap from building to building and consume major portions of an entire city, as has happened in San Francisco.
There have in the past been valves designed to implement the purpose of checking fluid flow during a trauma, and some such valves utilize a balanced ball for the valve triggering element as does applicant. Salient among such art are the following U.S. Patents: U.S. Pat. No. 1,742,685 issued to A. H. Brandon on Jan. 7, 1930, and U.S. Pat. No. 2,615,461 issued to W. W. Crow on Oct. 28, 1952. Both of these valves were provided to protect dwellings and other buildings against gas flow during earthquakes and utilize a balanced ball. Two other patents were issued to E. N. Yeamans on Mar. 26, 1918, and May 6, 1919, having U.S. Pat. Nos. 1,260,739 and 1,302,749, respectively. The latter two valves utilize a balanced ball principle and deploy the valves on railroad locomotives to terminate boiler steam flow into the operational areas of the locomotive in case of overturn of the train.
The above cited valves would of course technically operate according to the principles described therein, but are somewhat complicated in their implementation and thus questionable in their reliability. It is naturally desirable in such an application that the valve be of the utmost simplicity and construction to minimize the tendency to malfunction as the valve may be in place for years without ever being operated. It is also highly desirable that the valve be very quickly and easily checked so that it may be periodically determined that the valve is still in working order.